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from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GL import shaders
from pyrr import matrix44
import numpy as np
from particles import GasFlow, HardSphereSetup, grid_of_random_velocity_particles
def on_timer(t):
glutTimerFunc(t, on_timer, t)
glutPostRedisplay()
def get_projection(width, height):
world_height = 1.0
world_width = world_height / height * width
pixels_per_unit = height / world_height
projection = matrix44.create_orthogonal_projection(-world_width/2, world_width/2, -world_height/2, world_height/2, -1, 1)
translation = matrix44.create_from_translation([-1.0/2, -1.0/2, 0])
return (np.matmul(translation, projection), pixels_per_unit)
def on_reshape(width, height):
global projection, pixels_per_unit
glViewport(0,0,width,height)
projection, pixels_per_unit = get_projection(width, height)
glutInit()
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH)
glutInitWindowPosition(0, 0)
window = glutCreateWindow("gas")
glutTimerFunc(10, on_timer, 10)
fragment_shader = shaders.compileShader("""
#version 430
in vec3 color;
void main(){
if (length(gl_PointCoord - vec2(0.5)) > 0.5) {
discard;
}
gl_FragColor = vec4(color.xyz, 0.0);
}""", GL_FRAGMENT_SHADER)
particle_shader = shaders.compileShader("""
#version 430
layout (location=0) in vec2 particles;
out vec3 color;
uniform mat4 projection;
void main() {
gl_Position = projection * vec4(particles, 0., 1.);
color = vec3(0.0);
}""", GL_VERTEX_SHADER)
particle_program = shaders.compileProgram(particle_shader, fragment_shader)
background_fragment_shader = shaders.compileShader("""
#version 430
in vec3 color;
void main(){
gl_FragColor = vec4(color.xyz, 0.0);
}""", GL_FRAGMENT_SHADER)
background_vertex_shader = shaders.compileShader("""
#version 430
in vec3 vertex;
out vec3 color;
uniform mat4 projection;
uniform vec3 face_color;
void main() {
gl_Position = projection * vec4(vertex, 1.);
color = face_color;
}""", GL_VERTEX_SHADER)
background_program = shaders.compileProgram(background_vertex_shader, background_fragment_shader)
particle_projection_id = shaders.glGetUniformLocation(particle_program, 'projection')
background_projection_id = shaders.glGetUniformLocation(background_program, 'projection')
background_color_id = shaders.glGetUniformLocation(background_program, 'face_color')
class View:
def __init__(self, gas):
self.gas = gas
self.energy = 0
self.tracer = [ ]
def update_trace(self):
positions = self.gas.get_positions()
self.tracer.append((positions[5][0],positions[5][1]))
if len(self.tracer) > 100:
self.tracer.pop(0)
def draw_trace(self):
glUniform3f(background_color_id, 1., 0., 0.)
glLineWidth(2)
glBegin(GL_LINE_STRIP)
for v in self.tracer:
glVertex(*v, 0.)
glEnd()
def on_display(self):
for i in range(0,10):
self.gas.evolve()
glClearColor(0.4,0.4,0.4,1.)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
shaders.glUseProgram(background_program)
glUniformMatrix4fv(background_projection_id, 1, False, np.asfortranarray(projection))
glUniform3f(background_color_id, 1., 1., 1.)
glBegin(GL_TRIANGLE_STRIP)
glVertex(0.,0.,0.)
glVertex(1.,0.,0.)
glVertex(0.,1.,0.)
glVertex(1.,1.,0.)
glEnd()
if trace:
self.draw_trace()
shaders.glUseProgram(particle_program)
glUniformMatrix4fv(particle_projection_id, 1, False, np.asfortranarray(projection))
glEnable(GL_POINT_SPRITE)
glPointSize(2*radius*pixels_per_unit)
gas.gl_draw_particles()
glutSwapBuffers()
if trace:
self.update_trace()
velocities = gas.get_velocities()
energy = np.sum(np.array([np.linalg.norm(v)**2 for v in velocities]))
if abs(energy - self.energy) > 1e-4:
print("energy = %.05f" % energy)
self.energy = energy
grid_width = 10
radius = 0.005
char_u = 1
trace = True
config = HardSphereSetup(radius, char_u, *grid_of_random_velocity_particles(grid_width, radius, char_u))
gas = GasFlow(config, opengl = True)
view = View(gas)
glutDisplayFunc(view.on_display)
glutReshapeFunc(on_reshape)
glutMainLoop()
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